PURPOSE: To reduce harmonic components in a DC feeding unit such as a subway and feed it with high reliability by using a 12-phase rectification system in a feeding system and a double section system provided with an intermediate dead section.

CONSTITUTION: The harmonic components contained in the current of the commercial frequency power supply 1 side is reduced by feeding every feeders 121 to 122 from 12-phase rectification system thyristor rectifiers 41 to 44. In addition, intermediate dead sections 112 and 114 are additionally spaced at regular intervals from the existing dead sections 111 and 113 and thyristor breakers 151 and 152 and the inverse parallel circuit of diodes 62, 64, 66, and 68 are connected in series and then desired running power is taken off from the respective both ends and bridged points. As a result, even when an electric motor car arrives while the feeder line is faulty, excessive bypass current is not applied to the electric motor car and the destruction of pantographs and dead sections can be prevented previously.